Cagrilintide: how the amylin agonist acts and the combination with semaglutide

What is cagrilintide?

Cagrilintide is a long-acting amylin agonist (sometimes referred to as an “amylin analogue”). Amylin is a hormone secreted together with insulin by the beta cells of the pancreas and plays a key role in regulating satiety, delaying gastric emptying and suppressing glucagon. Deficiency of, or reduced sensitivity to, amylin has been described in people with obesity and/or type 2 diabetes, which is one of the factors behind increased appetite and “food noise”. The idea behind cagrilintide is the restoration of this signal in the brain and the gastrointestinal tract in a predictable, weekly pattern.

At the molecular level, cagrilintide acts through amylin receptors (AMYs) — heterodimeric complexes between the calcitonin receptor (CTR) and the so-called RAMPs (receptor activity-modifying proteins 1-3). This “two-component” architecture explains why different agonists (amylin, calcitonin and synthetic analogues) can have different selectivity and action. New structural dynamics studies show that cagrilintide binds in a way similar to amylin, but causes specific conformational changes in the CTR+RAMP complex, which probably contribute to its clinical efficacy.

Mechanism of action: “satiety axes” beyond GLP-1

Cagrilintide regulates several key processes:

• Increases the feeling of satiety and reduces overeating. Amylin signalling in the brain's appetite centres leads to lower spontaneous calorie intake and a “quiet mind” about food.

• Slows gastric emptying. Slower gastric transit prolongs the feeling of fullness after eating.

• Regulates glucose-homeostasis hormones. Suppression of glucagon after a meal contributes to more stable post-meal glycaemia.

It is important that the amylin axis differs from GLP-1, although the effects on appetite and gastrointestinal motility overlap. This complementarity is the basis of the interest in combining cagrilintide with semaglutide (a GLP-1 agonist) to achieve deeper and more lasting weight loss.

Pharmacokinetics: designed for once-weekly administration

In early human trials, cagrilintide showed a long half-life of ~159–195 hours (6.5–8 days) and a tmax of 24–72 hours, with a profile that supports weekly dosing — similar to semaglutide (GLP-1) in terms of convenience, but on a different biological axis. This matters for adherence and real-world effectiveness in practice.

What do the clinical data show for cagrilintide as monotherapy?

The first larger published trial in overweight/obese (non-diabetic) people showed that cagrilintide, administered once a week, resulted in a clinically significant, dose-dependent weight reduction over a period of 26 weeks, with the highest doses achieving ~10.8% of baseline weight (according to the trial-product estimand), superior to placebo. The tolerability profile was good and comparable to the expected gastrointestinal effects for the class (nausea, vomiting, diarrhoea) - mostly mild to moderate.

This put cagrilintide on the map as a promising amylin agonist, capable of achieving independent results close to some of the published results of GLP-1 therapies, but with a different mechanism — a valuable alternative and an even more valuable partner in combination.

Why is the combination with semaglutide (CS10) attracting so much attention?

When two satiety axes are combined — GLP-1 (semaglutide) and amylin (cagrilintide), the effects on appetite, gastric transit and energy intake are enhanced. This was demonstrated in a randomised phase 2 trial, where co-administration led to greater weight reduction than either agent alone — with good tolerability.

The Phase 3a data from the REDEFINE programme were also published in June 2025, with simultaneous publications in the scientific journal NEJM and the ADA Scientific Sessions. In brief, the combination of cagrilintide + semaglutide led to significantly greater weight reduction compared with placebo and with each agent separately, both in people without diabetes (REDEFINE-1) and in people with type 2 diabetes (REDEFINE-2). Various reports and sub-analyses mention mean reductions of around 20-23% at 68 weeks in the non-diabetic population, and in type 2 diabetes, a double-digit reduction superior to the control group.

Context: The numbers vary depending on the statistical method, the populations and the adherence analysis — so it is correct to speak of ranges of values and not of a single “magic” figure. Still, the consistent signal is clear: the two mechanisms together achieve a greater mean reduction.

 

Safety and tolerability: what to expect based on published data

As with GLP-1, the most common adverse events with cagrilintide and its combination are gastrointestinal (nausea, vomiting, diarrhoea, constipation), usually mild to moderate and transient. In the combination studies and in REDEFINE, the safety profile is described as consistent with the known class effects, with no new major signals. Of course, a full assessment requires official labelling documents and post-approval monitoring.

Important (YMYL): This text is intended for educational purposes only and does not constitute medical advice. Decisions about diagnosis, treatment, dosing and combination must be made only by a healthcare professional, in accordance with the official product information.

Where does cagrilintide fit in the “new wave” of weight therapies?

After the strong results of GLP-1 and GLP-1/GIP agonists (semaglutide, tirzepatide), interest has shifted to new hormonal “axes” and combinations: amylin mimetics (such as cagrilintide), triple agonists (e.g., retatrutide) and multi-targeted molecules. In this landscape, cagrilintide is mechanistically distinct and in combination with semaglutide (CS10) has shown weight reductions that in some analyses match or exceed some of the published values for other classes - an important message that complementary hormones may be the road to more complete and lasting efficacy.

TLDR

• Different biology, similar convenience. Cagrilintide is a long-acting medicine given once a week, similar to semaglutide — but it acts through amylin receptors, not through GLP-1.

• On its own and as a team. As monotherapy, it shows significant weight loss at 26 weeks. In combination with semaglutide, an even greater mean reduction in larger trials (68 weeks).

• Expectations should be realistic. As with GLP-1, individual response varies and a “plateau” is a normal phase. When treatment is stopped, part of the lost weight is usually regained — a characteristic of all behavioural and pharmacological weight-reduction interventions. (This phenomenon has also been shown with GLP-1 in separate trials.)

• Safety and labelling. Actual use, indications, contraindications and risks depend on the official product information and medical judgement.

Frequently asked questions (FAQ)

What is cagrilintide?

Long-acting amylin agonist for once-weekly administration. It enhances the feeling of satiety, delays gastric emptying and promotes weight reduction through amylin receptors (CTR+RAMP).

How does it differ from semaglutide?

Semaglutide is a GLP-1 agonist. Cagrilintide targets amylin receptors. The two mechanisms are complementary.

What results have been shown in studies?

As monotherapy: up to ~10.8% on average over 26 weeks · in combination with semaglutide: ~20–23% on average over 68 weeks in non-diabetic populations; in T2D, double-digit reductions with superiority over the control groups. The numbers vary depending on the analysis and the population.

What are the most common side effects?

Mainly gastrointestinal (nausea, vomiting, diarrhoea/constipation), most often mild to moderate — similar to the GLP-1 classes. Details depend on the official labelling.

Sources

• Phase 3a, cagrilintide + semaglutide combination: publications in NEJM and summaries from ADA 2025. Greater weight reduction compared with placebo/monotherapies.

• Phase 2, cagrilintide monotherapy (26 weeks): The Lancet / PubMed — dose-dependent reduction up to ~10.8% and good tolerability.

• Phase 2, cagrilintide + semaglutide combination versus each monotherapy: greater effect and expected safety profile.

• Pharmacokinetics (t½ ~159–195 hours; tmax 24–72 hours): phase 1b data for cagrilintide; weekly regimen.

• Mechanism and receptors (CTR+RAMP): review and structural publications.